1. Field of the Invention
The present invention relates to a network device management unit, a network device management system, and a communication management unit, and more particularly, to consolidated management of devices connectable to each other and operable in a network environment.
2. Description of the Background Art
Recently, Internet telephony technology, connecting at least two telephone units via an IP network (Internet Protocol network), has become available. For example, VoIP (Voice over IP) can be used for IP phone communication between telephone units. VoIP is implemented by SIP (Session Initiation Protocol), H.323, or the like. SIP in particularly is widely applicable not only to VoIP but also to other real-time communication systems that use signaling control process.
Further, SIP will be adopted as the standard protocol for a so-called NGN (Next Generation Network), which is now undergoing standardization. SIP is used to start a communication between terminal devices, or one terminal device and a server, in an NGN environment. In the NGN environment, terminal devices such as a telephone or the like may be controlled or managed by SIP. With such configuration, multiple services can be seamlessly organized.
For example, in households, a cell-phone can be used as a cordless handset of a land-line phone, by which a service charge can be reduced. Further, a triple play service such as using TV phones, viewing image contents, and viewing a web page at the same time can be made available.
JP-2006-135954-A discusses a method of providing services by using signaling control, in which a television conference system is devised by combining a voice communication device, connected to a telephone network, and a video/image communication device, connected to a public line network such as the Internet.
Further, JP-2006-319697-A discusses a method of establishing sessions for image processing devices connected to corresponding IP phones when sessions for IP phones are established.
Recently, several services such as telephone, facsimile, IM (instant messenger), and television conferencing can be implemented using SIP and communication devices such as a real-time communication device. The number or types of such communication devices is increasing, providing users with a variety of services to increase user convenience for information handling. However, because such communication devices are provided by multiple vendors, it becomes difficult to set up a more effective communication environment that can link these various services.
For example, typically available television conference systems use a voice communication system and a video/image communication system as one combination. However, the voice communication system and the video/image communication system are typically provided by multiple vendors using unique systems, by which a television conference system composed of a combination of multiple systems may be hard to implement. Further, with the above-mentioned triple-play service, each household must install a set-top-box having the same functions.
JP-2006-135954-A and JP-2006-319697-A disclose methods of providing one service by linking a plurality of different devices. However, JP-2006-135954-A aims for a TV phone, which combines a telephone and a television, and therefore devices other than telephones and televisions may not be employed in such system. Further, JP-2006-319697-A requires that special processing is carried out by each device.